Processors of all computers, whether micro, mini or mainframe must have.
Processors of all computers, whether micro, mini or mainframe must have ALU,Primary storage and Control Unit.
An arithmetic-logic unit (ALU) is the part of a computer processor (CPU) that carries out arithmetic and logic operations on the operands in computer instruction words. In some processors, the ALU is divided into two units, an arithmetic unit (AU) and a logic unit (LU).
In this case, primary storage typically refers to random access memory (RAM), while secondary storage refers to the computer's internal hard drive. RAM, commonly called "memory," is considered primary storage, since it stores data that is directly accessible by the computer's CPU.
The control unit (CU) is a component of a computer's central processing unit (CPU) that directs the operation of the processor. It tells the computer's memory, arithmetic/logic unit and input and output devices how to respond to the instructions that have been sent to the processor.